Understanding HTTP Flood Attacks: A Growing Threat in India

By Aman Madhok

In today’s digitally connected world, the internet plays a pivotal role in our daily lives. Businesses, organizations, and individuals rely on web services for various purposes, making web servers a prime target for cyberattacks. The internet has become an essential part of our daily lives. With the growth of online services and businesses, the need for robust cybersecurity measures has never been greater. Among the various cyber threats that organizations face Distributed Denial of Service (DDoS) attacks have gained notoriety for their potential to disrupt websites and online services. A DDoS attack is a malicious attempt to disrupt the normal functioning of a network, service, website, or online application by overwhelming it with a flood of traffic from multiple sources. The goal of a DDoS attack is to make the targeted resource unavailable to its intended users, causing service disruptions or downtime. According to a report of 2022, India is the second-largest source of HTTP-based DDoS attack traffic which witnessed an increase of 61% YoY.

HTTP Flood are on the rise exponentially! But what are they?

HTTP Flood attacks have been around for a few years, they are sometimes considered old news. However, these attacks are more sophisticated and aggressive than traditional DDoS attacks. An HTTPS flood, also known as an SSL flood, is a type of Distributed Denial of Service (DDoS) attack in which the attacker overwhelms a target website or online service with a large volume of HTTPS (Hypertext Transfer Protocol Secure) requests. HTTPS is the secure version of HTTP, used for encrypting data transmitted between a user’s browser and a web server. It provides confidentiality and data integrity.

In an HTTP flood attack, the attacker floods the target server with a massive number of HTTP requests, typically overloading the server’s resources such as its CPU, memory, or network bandwidth. This flood of requests can make the server unable to respond to legitimate user requests, causing a denial of service to users trying to access the website or online service.

Characteristics of HTTP Flood Attacks

• High Volume of Requests: HTTP flood attacks involve an exceptionally high volume of HTTP requests, often originating from a botnet, which is a network of compromised computers.
• Uniform Resource Locators (URLs): Attackers may target specific URLs, such as login pages or resource-intensive functions, to maximize the impact.
• Spoofed IPs: Attackers may employ IP spoofing techniques to make it appear as if the requests are coming from various sources, making detection and mitigation more challenging.
• Variability: HTTP flood attacks can vary in terms of their intensity and duration. Some may be short-lived bursts, while others can be prolonged attacks.
• Legitimate User Agents: To further blend in with legitimate traffic, attackers may use common user agent strings to make it difficult for security measures to differentiate between real users and malicious requests.

What makes HTTP Floods especially harmful is that they’re hard to detect and differentiate from legitimate traffic. They are standard URL requests. And because they are lower bandwidth attacks as opposed to volumetric attacks they fly under the radar more easily. That is until it’s finally revealed just how much damage they have done. In June of this year, an organization was hit with an HTTP Flood that resulted in over 45 million requests. For comparison purposes, it was the equivalent of Wikipedia’s daily requests occurring in less than 10 seconds. A server doesn’t exist that can handle that. Here are some factors to consider regarding the harm caused by HTTPS flood attacks:

• Service Disruption: The primary goal of an HTTPS flood is to disrupt the target’s online services. When a web server is overwhelmed with a flood of SSL/TLS handshake requests, it can become slow or completely unresponsive to legitimate user requests.
• Financial Impact: Downtime caused by a DDoS attack can result in significant financial losses for businesses, especially if they rely on their online presence for revenue generation. Loss of sales, productivity, and customer trust can be harmful.
• Reputation Damage: Suffering from a DDoS attack can harm an organization’s reputation, as customers may become frustrated with the inability to access their services and may perceive the organization as unreliable.
• Resource Consumption: HTTPS flood attacks can consume a significant amount of network bandwidth, server resources (CPU and memory), and potentially exhaust the server’s SSL/TLS processing capacity. This can lead to additional operational costs for mitigating the attack and potentially upgrading infrastructure.
• Security Risk: While the HTTPS flood itself doesn’t directly compromise data or access sensitive information, it can serve as a smokescreen for other malicious activities. During a DDoS attack, security teams may be distracted, allowing attackers to exploit vulnerabilities or conduct other malicious actions.
• Mitigation Costs: Organizations often need to invest in DDoS mitigation solutions and services to protect against HTTPS flood attacks. These costs can add up, especially for large-scale attacks.
• Legal and Regulatory Consequences: Depending on the nature of the attack and its impact, there may be legal and regulatory consequences for the perpetrators if they are identified.
• Customer Trust: Prolonged or frequent DDoS attacks can erode customer trust, as users may start to question the security and reliability of the targeted service.

Mitigation Strategies

To defend against HTTP flood attacks, organizations should implement a combination of proactive and reactive measures:

• Traffic Analysis: Employ traffic analysis tools to monitor and analyze incoming traffic patterns. This helps identify abnormal traffic spikes indicative of an ongoing attack.
• Rate Limiting: Implement rate-limiting rules to restrict the number of requests a single IP address or user agent can make within a given time frame.
• Content Delivery Networks (CDNs): Use CDNs to distribute traffic and absorb DDoS attacks, preventing them from reaching the origin server.
• Web Application Firewalls (WAFs): WAFs can filter and block malicious traffic based on predefined rules, helping to identify and mitigate HTTP flood attacks.
• IP Whitelisting/Blacklisting: Maintain a list of trusted IPs (whitelisting) and known malicious IPs (blacklisting) to allow or deny access accordingly.
• Scalability: Ensure the server infrastructure is scalable, allowing for the rapid allocation of additional resources during traffic spikes.
• Anomaly Detection: Implement anomaly detection systems that can identify unusual traffic patterns and trigger automatic countermeasures.
• Incident Response Plan: Develop a comprehensive incident response plan that outlines the steps to be taken in case of an HTTP flood attack.

To mitigate the harm caused by HTTPS flood attacks, organizations typically employ DDoS protection solutions, such as Content Delivery Networks (CDNs), traffic scrubbing services, and application layer security measures, to filter out malicious traffic and allow legitimate traffic to reach their servers. It’s important to note that the harm caused by DDoS attacks can vary widely depending on factors such as the attacker’s resources, the target’s defenses, and the motivation behind the attack. Organizations should have robust DDoS mitigation strategies in place to minimize the impact of such attacks. This is a reason so many organizations, enterprises and governments rely on Radware to provide industry-leading IT security to remain safe and operate at optimal levels. Our experts have one goal in mind keep customers secure by detecting and stopping attacks before they overwhelm their infrastructure

(The author is Aman Madhok, Regional Director – Govt., PSU, Telco – India, SAARC & Middle East, Radware, and the views expressed in this article are his own)